Process of blast combustion.



PATENTED FEB. 13, 1906.

B. E. BLDRED.

PROCESS OP BLAST COMBUSTION.

APPLIGATION FILED un. s. 1905.

/W um L4M WITNESSES:

UNITED s'rAlrJlJs PNT. oFFIoE.

BYRON E. ELDRED, BRONXVILLE, NEW, YORK, ASSIGNOR TO COMBIIS- TION UTILITIES COMPANY, OF NEW YORK, N. Y., A CORPORATION OF NEW YORK PROCESS O F BLAST C OMBUSTION.

Specification of Letters Patent. Appnmion mea April s, 1905. .serial No. 254.476.

Patented Feb. 13. i906.

- To all whom it may concern:

ing solid, li uid, or gaseous fuel introducedl under prou sion b blast or slmilar agency x5- Be it known that I, BYRON E. ELDRED, a citizen of the United States, residing at Bronxville, inthe county of Westchester and State of New York, have invented certain new and useful Improvements in Processes of Blast Combustion, of which the following Yllrliecification and accompanying drawings ustrate the invention in a form which I now regard as the best out of the various forms in which it may be embodied.

' This invention relates to a process of burninto a com ustion-c amber without revious Aignition in the form of a streamc oud, or .current in a finely divided, pulverized,

sprayed, atomized, gaseous, or similar condition. It relates to the productlon of a slowburnin flame by employing a draft-current of air iluted with a redetermined amount of neutral gaseous di uent, somewhat as described in my prior patent, No. 692,257.

In particular the invention a lies tothe concentrated fuels of hi h calo c powersuch as owdered co'a oil, natural gas, &o.-as istinguished from weaker fuels, such as roducer-gas, although it might be used witfl these latter where a very low flame temperature is needed. As previously pracl ticed the method of introducing these concentrated carbonaceous fuels into furnaces by blast or current, generally in long furnaces of the reverberatory ty e, has resulted in ver hightemperatures w1t thecombustion-c amber, and while of recognized efficiency in causing the combustion to take lace largel in the region of the objects to be heated andY over a considerable length `of space this method has not, so far as I am aware, hitherto been made practical in-arts requiring a comparatively low temperature,

a regulated temlpature, or a wide ran e of tem erature. ong the injurious e ects pro uced by an exoessivel -hot blast-flame -1s the rapid destruction of nings which ensues, often making necessary the use of means to prevent impingement o the flame on the lining, thereby sacrificing part of its efficiency.

By employing as an ingredient of the blast a gaseous diluent, such as products of substantially complete Acombustion equivalent in volume to a small portion of the stackgases from the furnace or othersource, I am enabled to control the tem erature and volume of the ame andthe uration of its combustion. These gases should preferably be completely burned out of combustible, or

substantially so, but may contain uncombined oxygen. The flame may thus be rendered longer, more voluminous, slow-burning, and cooler and a plicable to ractically ,all of the uses to W ch long b asteflames have been successfully applied and to many others for which they have hitherto been unsuitable. The flame may be allowed to iminge onthe furnace-linings with much less estructive effect than heretofore, which is a veri important consideration and forms one of t e chief advantages of my invention` The invention also relatesto the production of locally -intensified combustion b means auxiliary to the main blast. ASpeci ically, where a local high temperature or a greater or less range o temperature is desired I provide for obtaining it by intensifying the combustion of a portion of the thusmodied blast or flame by means of an auxiliary jet or ets of a suitable gas or mixture of gases, re erably directed counter or at an an le to t e axis of the flame and adapted to de ect and agitate only a part of the combustible stream. This `gas is preferably a .a heat-retaining region in which the ignition of the flame is maintained and its combustion carried to substantial completion when the` fuel and air are furnished in proportions essential to perfect combustion. Premature chilling of the inflated fiame would tend to cause incomplete combustion. rials as mineral solids, being of a heatretent ive incandescing character-thatv is to say,

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Such mateincandescing objects or materialslorthose capable under the' conditions vof treatment of attaining a temperature of incandescence# may be subJected to im ingement of the flame without undue chil 'ng of the latter.

On the hearth or floor 2 are supported the materlals under treatment, such as ore undergomg a roasting or smelting operation,

.Portland-cement material' which is being calcined and sintered, or other materials. The materials may be fed in at one end by aconveyer 3 and propelled along the hearth toan outlet 4 by means of rabbles 5. The particular means of introducing, feeding or removing'the materials forms, no part of the invention and may be as desired. v In other words, I do not broadly confine m self to. any pal'- ticular form of furnace, alt ough preferably employing a. reverberatory furnace. Where the materials re uire to be fed along the hearth, lthis may e done in any convenient Way-as, for example, in a rotary inclinedbarrel cement-furnace'.

At one end is the stack or chimney 6 and'v atA the other is a blast-nozzle 7 directed longitudinally of the combustionchamber. nto this nozzle is fed b.. vknown. means .pulverized coal 8, propelled y a draft-current from .a pipe 9, Which connects with the chimney 6 and contains a fan-blower 10. If a different fuel is used, such as oil or as, the fuel-feeding arrangements will be t ose suited to the Y particular fuel employed. On the suction.

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side ofthe fan is an air-inlet 11, in which and thetrunk of the pipe are valvesv or dampers 12 13 forlre latng the proportions of air andproducts o combustion used in the blast.

14fis an auxiliary pipe leading from an aircompressor 15 and terminating in a jet-nozzle 16 above the main Iblast-nozzle and directedl at an angle downwardly toward thev that is, referably only a small portion ofthe.

total vo ume of the stack-gases-I retard the union ofthe oxygen and combustible, thereby modifying, lengthening, and ina-ting the flame and reducing its natural temperature. Theproportion ofy the total stack-gases returned and passed through the fire may be gases.

varied .more or less, depending uponthe conditions; but I have obtained satisfactory results by returning'about ten per bent. lof the The temperature of the flame is under control Without vvarying the ratio of-air ,to combustible, since b increasing the proportion of diluent the ame may be lengthened and reduced inl temperature-and byreducing the proportion it may lie-.shortened and made hotter. It -is in any event, if allowed to full. develop, longer, more'dffuse, and cooler t an a iiame producedv with the same quantit and proportions of fuel and air alone in t e blast. The Whole quantity of airnecessary to a complete combustion of the main flame may be introduced with the fuel' in the blast-current or. a portion may be added Within the combustion-chamber; but

I prefer the former method, since it affords better control of combustion. ture of the flame i'n general tends to be her than a flame produced with an external elbed and a dilute .air-draft, as specifically de'- scribed in my 'Patent No. 692,257.

The tempera- Y' The auxiliary airjet from nozzle 16 by deflecting and agitatinga portion of the combustible stream lproduces a localA hightemperatu-re, which, as shown, operates upon the materialv just prior to its discharge'into the outlet 4. It might operate at a different point or oints. Such local temperature ma e useful, for example, in effecting the fina sinter" or formation of cement clinkers after the -ime in the-cement mate-- rial hasbeen calcined by the cooler part of the flame and in actingA on refractory ores. The burning-of cement was made the subject of a se arate application, SerialNo. 254,474, iiled pril 8f, 19.05, on which Patent No.

797506WasgrantedAu ust 15,1905. Owi'n to the concentrated c aracter of the fue. the auxiliary 4jet Will afford an extraordinarily h temperature, if required, While the main ame is much cooler. The maximum may be reduced by modifying the velocity or volurne of the jet or by diluting' it, so. that a smaller range of tem `erature results.

17 is a diluent-supp y pipe branchin from pipe @and discharging concentric with t e jetnozzle lunder suction of the jet, whereby the jetis diluted. Valves 18 19-re late the roport'ions and velocity of the di nte jet. t is obviousV that the jet or jets lmay be so placed asto obtain localized temperatures at different oints or over an extended area. The auxi iary gaseous jet may be omitted Where its effect is not required.

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The comparative coolness and difl'useness o f the main arne, besides'exerti a beneficial eect in the heating1 operatlon, tends to avoid destruction of t Moreover, the greater volume of. the blast-current and its-retarded combustion due to the diluent gas enable the blast to be reduced in strength, whilemaintaining a very'long flame,

and Without added danger ofl backfrmgor.

ex losion. Vhile aware that prio-r patents have been granted purporting to show the use of ulverized fuel, together with stack-gases, I elieve myself to be the first Who has-aimed tosecure or has industrially applied with the agents e furnace-lining.

herein described a long slow-burning voluminous flame in a reverberatory chamber or elsewhere or a locally-intensified combustion of the character specified.

The heat losses due to excess of air employed for combustion are by my process materially reduced, inasmuch as the slow drawn-out combustion produced allows of the substantial completion of combustion with a minimum amount of air or oXy en. The stack-gases resultin from this met od of combustion are there ore, generally considered, richer in CO2 than ordinary stackgases. A

What I claim as new, and desire to secure by Letters Patent, is-

1. The process of producin a voluminous flame of large heating area w 'ch consists in projecting into an unobstructed hot-walled chamber of refractory material an ignited blast of suspended fuel carried by air containing suflicient products of combustion to retard burning and completing the combustion by radiant heat from the walls.

2. The process of producing a voluminous flame of large heating area which consists in piojlecting into an unobstructed chamber wit roof of refractory heat-radiating material an ignited blast of suspended fuel carried by air containing sufficient products of combustion to retard burning and completing thef combustion by radiant heat from the roo 3. The process of producin a voluminous llame of large heating area which .consists in projecting into an unobstructed hot-walled chamber of refractory material a blast of powdered coal carried by air containing sufcient products of combustion to retard burning and completing the combustion by radiant heat from the walls.

4. The process of producin a voluminous flame of large heating areawich consists in projlecting into an unobstructed chamber wit roof of refractory heat-radiatin material a blast of powdered coal carrie by air containing sufficient products of combustion to retard burning and completing the combustion by radiant heat from the roof.

5.. The process of burning pulverized fuel whlch consists in projecting pulverized fuel into a reverberatory furnace in suspension in aforcible current composed yentirely of air and roducts of combustion, such products being 1n sufficlent amount to retard combustion by the air of the current and completing co'mbustion by radiant heat.

6. The Iprocess of producing differential heating w ich consists in fornung a voluminous flame of lar e heating area in an unobstructed hot-wa led chamber of refractory material b an ignited blast of suspended fuel carrie by air containin suffcientproducts of combustion to retar burning and locally intensifying combustion at a desired point by a cross-jet containing air.

7. The process of produclng diHerential heating which consists in formmg a voluminous flame of lar e heatin area 1n an unobstructed hot-wal ed cham er of refractory material by an ignited blast of suspended fuel carried by air containin sufficient products of combustion to retar burning and locally intensifying combustion at a desired point and to a desired degree by a cross-jet containing air and products of combustion in regulated proportions.

8. The herein-described process of intensifying the combustion of a blastcurrent of owdered coal diluted with products of comustion which consists in subjecting the same to the impingement of a high-pressure jet of a1r.

9. The process of intensifying the temperature of flame which consists in subjecting a fuel-laden current to im ingement by an airjet diluted with a neutra fixed gas.

10. The process of intensifylng the temerature of flame which consists 1n subjectmg a fuel-laden current to impingement by an air-jet diluted with gaseous products of combustion.

11. The process of intensifying the combustion of a blast-current of powdered fuel which consists in subjecting the same` to imingement by a high-pressure jet of air dil)uted with products of combustion.

12. The process of regulating the temperature of fiame which consists in subjectlng a fuelladen current to impingement by a jet of dilute air in such manner as to increase the normal temperature of combustion, and varying the proportion of diluent to air.

13. The process of obtaining regulated tem eratures in a furnace which consists in pro ucin a blast-ame of previously-unignited fue subjecting a current of the same composition to impinvement by a dilute airjet to locally intensi its combustion, and varying the proportion of diluent in the jet to vary the local temperature.

14. The process of obtaining regulated tem eratures in a furnace which consists in ro ucin a blast-flame of owdered coal diuted wit products of com ustion, acting on a similar current with an air-jet diluted with products'of combustion to obtain a local high temperature, and varying that temperature by varying the proportion of diluent to air in the 'et.

Irl testimon whereof I have hereunto set myhand, in t e presence of two subscribing Witnesses, the 1st day of April, 1905.

BYRON E. ELDRED.

-Witnessesz JAs. K. CLeRK, R. M. PIERsoN.

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